1. Field of the Invention
The present invention relates to a stereoscopic display device and an image displaying method thereof, more particularly, to a stereoscopic display device using a pair of polarizer glasses to obtain a stereoscopic image and the displaying method thereof.
2. Description of the Prior Art
By providing a vivid stereoscopic image for the observer, the stereoscopic display technology has become one of the major developing directions of modern displaying technologies. Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram of a conventional shutter-glasses-type stereoscopic display device, and FIG. 2 is an operating schematic diagram of a conventional shutter-glasses-type stereoscopic display device. As shown in FIG. 1, the shutter-glasses-type stereoscopic display device 1 comprises a display panel 10 and a pair of shutter glasses 12. When displaying images, the display panel 10 provides a left eye image 16 for the left eye and a right eye image 14 for the right eye alternately by scanning. When watching the displaying images, the shutter glasses 12 worn by the observer allows the target eye to catch the images from the display panel 10 and blocks the non-target eye to catch the images based on what is shown on the display panel 10. As shown in FIG. 2, the display panel 10 shows a flow chain of a complete frame according to the direction of the circular arrow. The detail of the flow chain is described below:
Time t1: The display panel 10 shows a complete right eye image 14, and all regions of the display panel 10 show the information for the right eye. At this time, the shutter glasses 12 will block the sight of the observer's left eye to make it not see the right eye image 14 displayed by the display panel 10, but allow the observer's right eye to see the right eye image 14 displayed by the display panel 10.
Time t2: Start to scan the left eye image 16. At this time, a small region of the display panel 10 shows the left eye image 16 but most of the regions remain the right eye image 14. The shutter glasses 12 still blocks the sight of the observer's left eye to make it not see the right eye image 14 displayed by the display panel 10, but allows the observer's right eye to see the right eye image 14. Since the right eye information shown by the display panel 10 is still much greater than the left eye information, so a small portion of the left image 16 will not affect too much. In order to reduce the disturbance from the left eye image 16 to the right eye, the right eye light transmission rate could be turned down, so the brightness of the left-eye image 16 captured by the observer will be lowered so as to reduce the disturbance from the left eye image 16 to the right eye.
Time t3: Keep scanning the left eye image 16. At this time more regions of the display panel 10 have shown the left eye image 16, causing an area of the left eye information similar to an area of the right eye information. In order to avoid interference, the shutter glasses 12 will block both the sight of the left eye and the right eye to prevent the observer receiving the mixed information.
Time t4: Keep scanning the left eye image 16. At this time most regions of the display panel 10 have shown the left eye image 16 but only a small region remain the right eye image 14. At this time the shutter glasses 12 will block the sight of the observer's right eye, but allow the observer's left eye to see the left eye image 16. Since the left eye information shown by the display panel 10 is already much greater than the right eye information, so a small portion of the right image 14 will not affect too much. In order to reduce the disturbance from the right eye image 14 to the left eye, the left eye light transmission rate could be turned down, so the brightness of the right eye image 14 captured by the observer will be lowered so as to reduce the disturbance from the right eye image 14 to the right eye.
Time t5: The display panel 10 shows a complete left eye image 16, and all regions of the display panel 10 show the information for the left eye. At this time, the shutter glasses 12 will block the sight of the observer's right eye to make it not see the left eye image 16 displayed by the display panel 10, but allow the observer's left eye to see the left eye image 16 displayed by the display panel 10.
At time t6, t7, t8, the display panel 10 will scan in accordance with the above-mentioned manner, beginning in scanning the right eye image 14, gradually transforming from the left eye image 16 to the right eye image 14, and the shutter glasses 12 will make the corresponding change, until the display panel 10 again shows the complete right eye image 14 at time t1.
From the above, we can see that in order to maintain the stereoscopic effect, images that contain both the left eye information and the right eye information that have no obvious difference must be partially discarded (e.g. the image at time t3 and time t7 in FIG. 2), or the observer will be perceptually confused when his left eye and right eye receive this image at one time. However, as part of the images can not be used, making the brightness and the frame rate of the conventional shutter-glasses-type stereoscopic display device 1 decreased and therefore lowing the display quality.
In addition, conventional technology further contains a space-type stereoscopic technology, which is accomplished when the display panel shows two sets of images for the left eye and the right eye respectively, making the observer's left eye only receive the left eye image, the right eye only receive the right eye image. However, because the display panel should show two sets of image at one time, in some cases the resolution will drop to 50%, causing the disadvantage of low-resolution.